Datasheet

DS26518 8-Port T1/E1/J1 Transceiver
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Register Name:
LRCR
Register Description:
LIU Receive Control Register
Register Address:
1008h + (20h x (n - 1)) : where n = 1 to 8
Bit # 7 6 5 4 3 2 1 0
Name RG703 — — — RTR RMONEN RSMS1 RSMS0
Default 0 0 0 0 0 0 0 0
Bit 7: Receive G.703 Clock (RG703).
If this bit is set, the receiver expects a 2.048MHz or 1.544MHz clock from
the RTIPn/RRINGn, based on the selection of T1 (1.544) or E1 (2.048) mode in the
LTRCR register.
Bit 3: Receiver Turns Ratio (RTR)
0 = Receive transformer turns ratio is 1:1.
1 = Receive transformer turns ratio is 2:1. This option should only be used in short-haul applications.
Note: Internal impedance match is not available for this mode.
Bit 2: Receiver Monitor Mode Enable (RMONEN)
0 = Disable receive monitor mode.
1 = Enable receive monitor mode. Resistive gain is added with the maximum sensitivity. The receiver
sensitivity is determined by RSMS1 and RSMS0.
Bits 1 and 0: Receiver Sensitivity/Monitor Gain Select (RSMS[1:0]).
These bits are used to select the receiver
sensitivity level and additional gain in monitoring applications. The monitor mode (RMONEN) adds resistive gain to
compensate for the signal loss caused by the isolation resistors. See
Table 10-22 and Table 10-23.
Table 10-22. Receiver Sensitivity Selection with Monitor Mode Disabled
RMONEN RSMS[1:0]
RECEIVER
MONITOR MODE
GAIN (dB)
RECEIVER SENSITIVITY
(MAX CABLE LOSS
ALLOWED) (dB)
0 00 0 12
0 01 0 20
0 10 0 30
0 11 0 36 for T1; 43 for E1
Table 10-23. Receiver Sensitivity Selection with Monitor Mode Enabled
RMONEN RSMS[1:0]
RECEIVER
MONITOR MODE
GAIN (dB)
RECEIVER SENSITIVITY
(MAX CABLE LOSS
ALLOWED) (dB)
1 00 14 30
1 01 20 22.5
1 10 26 17.5
1 11 32 12